Conventional ultrasonic welding devices include ultrasonic welding devices each provided with an anvil and an ultrasonic horn, wherein an object to be welded is sandwiched between the anvil and the ultrasonic horn, and in that state, ultrasonic vibration is applied to the ultrasonic horn, to weld as a result the object to be welded.
Known instances of such ultrasonic welding devices include a device that is provided with a holding member that holds an object to be welded, and an anvil roller that can move with respect to the holding member, between a welding area over which the object to be welded is welded between the ultrasonic horn and the anvil roller at a position where the anvil roller overlaps, in a plan view, with the object to be welded that is held on the holding member, and a non-welding area, across the object to be welded (see, for instance, Japanese Patent Application Publication No. 2012-76343).
In order to weld the object to be welded, it is necessary to bring the anvil roller close to the ultrasonic horn, at a region at which the object to be welded is present between the anvil roller and the ultrasonic horn, within the range of movement of the anvil roller. Conversely, it is necessary to draw the anvil away from the ultrasonic horn in order to suppress wear and degradation of the anvil roller and the ultrasonic horn, at a region at which the object to be welded is not present between the anvil roller and the ultrasonic horn, within the range of movement of the anvil roller.
The ultrasonic welding device disclosed in Japanese Patent Application Publication No. 2012-76343, therefore, has a driving mechanism for driving the anvil roller with respect to the ultrasonic horn in such a manner that the anvil roller approaches the ultrasonic horn in the welding area, and moves away from the ultrasonic horn in the non-welding area.
FIG. 14 is a side-view diagram illustrating the schematic configuration of a driving mechanism of the ultrasonic welding device disclosed in Japanese Patent Application Publication No. 2012-76343.
The driving mechanism disclosed in Japanese Patent Application Publication No. 2012-76343 is provided with: a horn holding member 103 that holds an ultrasonic horn 100; an anvil holding member 104 that is pivotably mounted on the horn holding member 103 about a pivot shaft 104a, and that holds an anvil roller 101 rotatably about a rotary shaft 101a; and a cylinder 105 that swings the anvil holding member 104 with respect to the horn holding member 103.
As illustrated in FIG. 14, the cylinder 105 contracts in such a manner that the anvil roller 101 moves away from the ultrasonic horn 100, in a state where anvil roller 101 has moved to a non-welding area across the object to be welded 106.
As illustrated in FIG. 15, the cylinder 105 extends in such a manner that the anvil roller 101 moves close to the ultrasonic horn 100, in a welding area over which the object to be welded 106 is welded.
In the driving mechanism disclosed in Japanese Patent Application Publication No. 2012-76343, however, the anvil roller 101 is caused to move close to or away from the ultrasonic horn 100 through extension and contraction of the cylinder 105, and, accordingly, both the cylinder 105 and a structure for powering the same are necessary herein, which causes a size of the ultrasonic welding device into larger. Further, complex driving control of the cylinder 105 is required in order to move the anvil roller 101 close to or away from the ultrasonic horn 100 in response to the movement between the welding area and the non-welding area.